The invention relates to a multiple flat-type switch consisting of foils of insulating material bonded to one another and having metallized contact surfaces and terminals, in which on the top side of a lower foil of insulating material, several contact areas with terminals are arranged, on which a central foil of insulating material is disposed which, within the area of the contact surfaces, is perforated, with a top foil of insulating material being arranged thereon which, on its bottom side and within the area of the holes, is provided with contact surfaces, as well as with terminals connected to the contact surfaces.
Multiple flat-type switches of the kind mentioned hereinbefore, are known, for example, from DE-OS No. 29 02 769, DE-OS No. 29 03 898 and DE-AS No. 26 60 067.
Such flat-type switches are frequently used with electronic equipment, such as with the keyboards of electric pocket calculators.
Conventional multiple flat-type switches, however, are unsuitable for certain practical applications in which the individual switches are required to have a large overtravel (overlift). By this it is understood that after a certain actuating path, the electric contacts are closed, but that subsequently thereto a further depression of the actuators must be possible, for example, that the entire actuating path for the switch must be long.
The path which the actuator is still capable of travelling after the closing of the contacts, is referred to as the overtravel. Such an overtravel, for example, is required in the case of switches which are intended to be triggered by the manual keys of a musical instrument. Conventional multiple flat-type switches, however, are unsuitable for effecting such an overtravel.
It is the object of the invention to provide a multiple flat-type switch of the kind referred to hereinbefore, in which the individual switches have a large overtravel.